STUDY ON ADHESION CHARACTERISTICS OF VIBRIO FLUVIALIS TO THE GILL MUCUS OF PSEUDOSCIAENA CROCEA

In order to get a better understanding of adhesion of pathogenic Vibrio fluvialis to the gill mucus of Pseudosciaena crocea,the influences of culture condition,bacterial density,culture stage,antibody treatment on the bacterial adhesion were investigated by indirect ELISA,successfully established by modifying various conditions.The results showed that the adhesion ability of V.fluvialis incubated in TSB was extremely stronger than that of V.fluvialis incubated in TSA(P0.01);the adhesive quantity of V.fluvialis increased with bacterial densities and peaked at 180 min post-incubation under 25℃;a saturation kinetics hyperbola:y = 0.1782ln(x) 1.6921(R 2 = 0.9810),was obtained by plotting adhered bacteria against the density of bacteria added;different adhesion abilities were showed when V.fluvialis at different culture stages.During 0 to 24 hour,the number of adhering bacteria increased with incubation time and reached peak at 24h,and then dropped sharply with the culture time extension.After the bacteria were treated with rabbit antiserum against O-antigen of V.fluvialis,the number of adhering bacteria reduced by 52%.All the results indicate that V.fluvialis can adhere to the skin mucus of P.crocea strongly in seawater by specific adhesion.However this kind of bacterial adhesion was not only remarkably influenced by environmental factors but also by culture conditions and nutrition level.These results are helpful for better understanding the characteristics of epidemiology and pathogenesis of V.fluvialis,which might be useful for the vibriosis control in fish culture.